/Engine/Source/Runtime/Slate/Public/Framework/MultiBox/MultiBoxBuilder.h
Adds any widget to the toolbar
void AddToolBarWidget ( [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > InWidget, const [TAttribute](API\Runtime\Core\Misc\TAttribute)< [FText](API\Runtime\Core\Internationalization\FText) > & InLabel, [FName](API\Runtime\Core\UObject\FName) InTutorialHighlightName, bool bSearchable )